TY - JOUR
T1 - Cosmic history and a candidate parent asteroid for the quasicrystal-bearing meteorite Khatyrka
AU - Meier, Matthias M.M.
AU - Bindi, Luca
AU - Heck, Philipp R.
AU - Neander, April I.
AU - Spring, Nicole H.
AU - Riebe, My E.I.
AU - Maden, Colin
AU - Baur, Heinrich
AU - Steinhardt, Paul J.
AU - Wieler, Rainer
AU - Busemann, Henner
N1 - Funding Information:
MM thanks J. Gilmour for the hospitality during his visit to SEAES. MM was supported by a Swiss National Science Foundation (SNSF) Ambizione grant ( PZ00P2_154874 ). LB was supported by the “Progetto di Ateneo 2015” issued by the Università di Firenze , Italy. PRH was funded by a grant from the Tawani Foundation . H. Busemann's work was supported by NCCR PlanetS funded by SNSF . The authors also thank Jean-Luc Margot, reviewers Gregory F. Herzog and Julia A. Cartwright, as well as two anonymous reviewers of an earlier version of the manuscript, for their comments.
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/5/15
Y1 - 2018/5/15
N2 - The unique CV-type meteorite Khatyrka is the only natural sample in which “quasicrystals” and associated crystalline Cu, Al-alloys, including khatyrkite and cupalite, have been found. They are suspected to have formed in the early Solar System. To better understand the origin of these exotic phases, and the relationship of Khatyrka to other CV chondrites, we have measured He and Ne in six individual, ∼40–μm-sized olivine grains from Khatyrka. We find a cosmic-ray exposure age of about 2–4 Ma (if the meteoroid was <3 m in diameter, more if it was larger). The U, Th–He ages of the olivine grains suggest that Khatyrka experienced a relatively recent (<600 Ma) shock event, which created pressure and temperature conditions sufficient to form both the quasicrystals and the high-pressure phases found in the meteorite. We propose that the parent body of Khatyrka is the large K-type asteroid 89 Julia, based on its peculiar, but matching reflectance spectrum, evidence for an impact/shock event within the last few 100 Ma (which formed the Julia family), and its location close to strong orbital resonances, so that the Khatyrka meteoroid could plausibly have reached Earth within its rather short cosmic-ray exposure age.
AB - The unique CV-type meteorite Khatyrka is the only natural sample in which “quasicrystals” and associated crystalline Cu, Al-alloys, including khatyrkite and cupalite, have been found. They are suspected to have formed in the early Solar System. To better understand the origin of these exotic phases, and the relationship of Khatyrka to other CV chondrites, we have measured He and Ne in six individual, ∼40–μm-sized olivine grains from Khatyrka. We find a cosmic-ray exposure age of about 2–4 Ma (if the meteoroid was <3 m in diameter, more if it was larger). The U, Th–He ages of the olivine grains suggest that Khatyrka experienced a relatively recent (<600 Ma) shock event, which created pressure and temperature conditions sufficient to form both the quasicrystals and the high-pressure phases found in the meteorite. We propose that the parent body of Khatyrka is the large K-type asteroid 89 Julia, based on its peculiar, but matching reflectance spectrum, evidence for an impact/shock event within the last few 100 Ma (which formed the Julia family), and its location close to strong orbital resonances, so that the Khatyrka meteoroid could plausibly have reached Earth within its rather short cosmic-ray exposure age.
KW - Solar System
KW - asteroids
KW - meteorites
KW - noble gases
KW - quasicrystals
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U2 - 10.1016/j.epsl.2018.03.025
DO - 10.1016/j.epsl.2018.03.025
M3 - Article
AN - SCOPUS:85044161969
SN - 0012-821X
VL - 490
SP - 122
EP - 131
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
ER -